Why are there always crushed stones near railway tracks?

A) The stones do not allow vegetation to grow on railway tracks.

B) To keep water from reaching the track on a regular basis and softening the ground.

C) To hold the wooden cross ties in place, which in turn hold the rails in place.

D) All of the above

Answer: D

Explanation: Crushed stones (ballast) along railway tracks stop vegetation, drain away water and hold the sleepers and rails in place, so all the reasons given are correct.